Liver damage in a neonate with alpha-1-antitrypsin deficiency due to phenotype PiZ null (Z-).

An infant with neonatal liver damage had α-1-antitrypsin deficiency, having inherited the Z allele from the father and the rare null allele from the mother. This indicates that while a lack of serum antiprotease predisposes to early liver disease, homozygosity for the Z allele is not essential.